1. Field of the Invention
The present invention generally relates to a method and system for controlling processors. In particular, the present invention relates to a method and system for dynamically controlling the operation speed of a general-purpose processor so as to reduce power dissipation.
2. Description of Related Arts
To enhance the computation and processing performance of the central processing unit (CPU), a faster operation speed is required. Therefore, the operating frequency of general personal computers (PCs) has increased from 33 MHz, 66 MHz, to 200 MHz and beyond. Thus, there is a need to integrate a greater number of transistors in a single CPU chip. However, the progress of the CPU operation speed has raised several practical problems.
Commonly, current CPUs are confronted with two interrelated issues: one is power dissipation, and the other is temperature. More power is required since a greater number of transistors are integrated together into a single chip and operated at high operating frequency. On the other hand, more heat is exhausted from CPU, thus raising the environmental temperature. These are important concerns to be settled.
Typically, a CPU can be cooled by mounting a heat spreader or a fan cooler thereon. Another approach is provided by means of so-called xe2x80x9cpower managementxe2x80x9d to reduce the power dissipation and thus lower the temperature. But there are some disadvantages inherent to the xe2x80x9cpower managementxe2x80x9d approach. For example, if the user utilizes power management on a CPU to lower the operation speed, partial reduction of power dissipation and temperature may be carried into effect. However, the executing efficiency for all application programs being run is cut down at the same time.
It is therefore an object of the present invention to provide a method and system for dynamically controlling the operation speed of a processor while simultaneously maintaining the executing efficiency by monitoring the operation performance of a CPU, and the purpose of reducing power dissipation and temperature can be achieved.
In the present invention, a control method for dynamically modulating operation speed of a processor includes the following steps. First, determine the utility ratio of said processor by intercepting idle signals sent to application programs from an operating system (OS) being executed by a CPU. Measure an occurrence frequency of said idle signals statistically, said occurrence frequency being related to the current utility ratio of said processor. Based on said occurrence frequency, control the CPU to perform at a fitting speed in proportion to the utility ratio. When the CPU is in low utility ratio, the operation speed is lowered to reduce power dissipation and temperature.
In addition, a control system for dynamically modulating the operation speed of a processor with respect to the present invention is disclosed to execute a program, for example OS, able to send idle signals. The control system includes an intercepting module for intercepting idle signals from a program being executed and a statistic module coupled to said intercepting module for determining the utility ratio of said processor corresponding to the intercepted idle signals, wherein an occurrence frequency of idle signals is measured to reflect the current utility ratio and a control module is coupled to said statistic module for controlling said processor to perform at an operation speed in proportion to the utility ratio.